I had the same problem even now in March 2019 with a 6.5 installation. Here is how I resolved it: Used a surprisingly easy Power CLI command
1- Install current version of VMware vSphere Power CLI
2- Shut down the VM you need to export
2- Connect the Power CLI app to your vCenter (when the power CLI launches it tells you the command to run to connect it to a vCenter FQDN)
3- Run this: >Export-VApp -Destination "C:\Directory" -VM "Name-of-vm-In-vCenter" -Format Ova
That's it, and I had a nice 14 Gig OVA file to use about 30 min later.